the.com/teaser

means A short preview or snippet designed to arouse curiosity about something without revealing the substance of it.

from Straightforward agent-noun formation: 'tease' plus '-er,' meaning one who (or that which) teases. 'Tease' itself traces back to Old English 'tæsan,' meaning to pull apart or comb fibers like wool — the literal plucking at strands evolved into the figurative sense of plucking at someone's patience or curiosity. The advertising sense of 'teaser' (a come-on that withholds the full picture) emerged in the 20th century, riding that same old metaphor: you're combing at the audience's attention, fiber by fiber, without ever handing over the whole fleece.